A comparative study of the physicochemical, microbial, and metabolic profiling of kimchi during long-term fermentation under varying salinity conditions

Abstract

In fermented foods, including kimchi, salinity is a crucial factor that influences preservation and quality. We aimed to investigate the physicochemical characteristics, microbiota, and metabolites of kimchi fermented at varying salinities over 200 days. Kimchi cabbages were soaked in 3%, 10%, and 20% (w/v) saline solutions for 10 h to prepare low-, middle-, and high-salinity kimchi, respectively. Although the salinity level of kimchi had a significant impact on its appearance, microbial community, and metabolite content in the early stages (until the 5th day), these differences diminished as fermentation progressed. The dominant lactic acid bacteria genera varied based on salinity, with Lactobacillus and Weissella proliferating in high-salinity kimchi, whereas Leuconostoc dominated regardless of salinity. During long-term fermentation, salinity influenced the levels of certain metabolites, including lactic acid, 4-aminobutyric acid, and putrescine. This study provides insights into the role of salt and the effects of salinity on kimchi quality during long-term fermentation.